A：這兩句都對。在非正式美式英語中，yet, already, just 和 ever 這幾個過去時間副詞，現今經常與簡單過去式連用，如 The bell just rang. (鈴剛響過)；I already saw him. (我看見過他)；Did you eat yet? (你吃了嗎?)。但在英式英語中，它們都使用現在完成式，如 The bell has just rung.；I’ve already seen him.；Have you eaten yet?
ever 的用法亦同，所以下面兩句的意思是一樣的：
- Did you ever go to mainland China? (你去過中國大陸嗎?)
- Have you ever been to mainland China?